1. Field of the Invention
The present invention relates to a fuel injection control device.
Priority is claimed on Japanese Patent Application No. 2003-364900, filed Oct. 24, 2003, the content of which is incorporated herein by reference.
2. Description of Related Art
A fuel injection control device has been known which controls the injection of fuel electrically order to enhance the efficiency of combustion. In a fuel injection valve of such a fuel injection control device, the opening and closing of the valve is performed by driving a movable iron core portion with the magnetic force which is generated by a solenoid (for example, refer to Japanese Patent Application, First Publication No. 2000-274329).
Furthermore, since it is necessary to control the fuel injection control amount minutely in order to enhance the efficiency of combustion, sometimes a piezoelectric element such as a piezo element or a magnetostrictive element or the like is utilized for opening and closing the fuel injection valve (for example, refer to Japanese Patent Application, First Publication No. H09-310655).
In recent years, in order to enhance the efficiency of combustion, so called direct injection type engines have come into use, in which the fuel is directly injected into the engine. With this type of engine, since the structure is such that the fuel which is compressed at a high pressure is sent to a fuel injection device which is provided at the cylinder head portion and is directly injected into the cylinders, accordingly a high pressure fuel pump, a high pressure fuel pipe, a fuel injection valve whose responsiveness is good, and a voltage elevation circuit which drives them all, are essential elements in the structure.
However, with a fuel injection valve of the former solenoid type, or with one of the latter type which utilizes a piezoelectric element or a magnetostrictive element or the like, there is the problem that the system as a whole becomes costly, since it is necessary to provide, as separate items, not only the voltage elevation circuit, but also a high pressure pump and a high pressure fuel pipe and the like.
Thus, the present invention proposes a fuel injection control device with which a reduction in cost can be anticipated, since the high pressure fuel pipe is made unnecessary by integrating together the fuel injection valve, whose responsiveness is good, and the high pressure fuel pump.